Struct JsonFrameBuffer 

pub struct JsonFrameBuffer { /* private fields */ }

Puts the pieces of a JSON stream back together and cuts it into whole top-level values.

Some WebSocket servers split one JSON message over several text frames, or glue several messages into one frame. Feed every received chunk to push. It keeps the unfinished tail and returns each complete top-level object or array.

What it does and does not do:

• It counts brackets and understands strings and escapes, so a brace inside "..." does not end a value.
• It does not check that the text is valid JSON. {not json} is returned as a complete value. Parse each returned string yourself.
• Only values that start with { or [ are recognised. If the pending text starts with anything else (a bare number, a word, a stray }), nothing is ever returned and the text stays in the buffer, growing with every chunk. Call reset when the stream is reconnected or corrupt.

Examples

use brokapi_sansio::{BufferPush, JsonFrameBuffer};

let mut buf = JsonFrameBuffer::new();

// One message arrives in two pieces.
assert_eq!(buf.push(r#"{"op":"quote","bid":"#), BufferPush::Incomplete);
assert_eq!(
    buf.push(r#"100}"#),
    BufferPush::Complete(vec![r#"{"op":"quote","bid":100}"#.to_string()]),
);

// Two messages arrive glued together, and a third starts.
let got = buf.push(r#"{"a":1} {"b":"}"} {"c""#);
assert_eq!(
    got,
    BufferPush::Complete(vec![r#"{"a":1}"#.to_string(), r#"{"b":"}"}"#.to_string()]),
);
assert_eq!(buf.pending(), r#"{"c""#);

// The caller can drop a half-received message, for example after a reconnect.
buf.reset();
assert!(buf.is_empty());

// Text that cannot start a value blocks the buffer, even if a good value follows it.
assert_eq!(buf.push(r#"oops {"a":1}"#), BufferPush::Incomplete);
assert!(!buf.is_empty());
buf.reset();

Implementations

impl JsonFrameBuffer

pub fn new() -> Self

Creates an empty buffer.

pub fn pending(&self) -> &str

The text received but not yet returned: an unfinished value, or text that cannot start one.

pub fn is_empty(&self) -> bool

Whether nothing is pending. Whitespace-only input counts as nothing.

pub fn push(&mut self, chunk: &str) -> BufferPush

Appends a chunk and returns every complete top-level value that is now available.

The returned strings are in arrival order. What follows them stays in the buffer. See the type docs for what is not checked.

pub fn reset(&mut self)

Throws away everything pending.

Trait Implementations

impl Clone for JsonFrameBuffer

fn clone(&self) -> JsonFrameBuffer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for JsonFrameBuffer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for JsonFrameBuffer

fn default() -> JsonFrameBuffer

Returns the “default value” for a type.